Many projects that develop information systems fail because system developers do not understand the user's requirements completely. The term “user” here means the customers that requests the software development to system developers. The reasons for failure include incomplete specifications of the user's requirements and the frequent changes thereof. We propose a new development method for a collaborative development model between users and system developers in developing Web application. In our method, users first create a part of the screen images and screen transition images in HTML. Next, the Web-app-skeleton generation tool we have developed, automatically generates a skeleton of the Web application from the HTML files. The system developers then add logical function to it. The Web-app-skeleton generation tool works to generate an optimal skeleton, after analyzing the structure of the HTML file, evaluating any similarity to other HTML files and clustering the pages. This paper describes the new user initiative collborative development environment. In addition, the prototype Web-app-skeleton generation tool is discussed and experimental results obtained from using the tool are reported.